There are many automobile sun visor structures having a mirror incorporated in their structure, at times known as "vanity mirrors", which are for the personal use of the passenger seated in the free front seat and even for the driver when his sun visor is equipped with such a mirror.
It is also known that such mirrors, in view of their location within the area of air flow inside the vehicle, tend to collect dust with ease and become dirty in relatively short periods of time. Such is the situation that, if they are not frequently cleaned, they become practically unusable. And to solve this drawback many known structures are provided with covers. The Spanish utility models Nos. 276352, 276353 and 276822 may be cited in this respect. In the first two references cited, there are described covers having a very simple structure, which have the drawback that when the mirror is uncovered, they hang freely and produce practical problems, which are accentuated above all when the vehicle is in movement, and also aesthetic problems.
The above Spanish utility model No. 276822 describes a cover which, when retracted, becomes concealed within the sun visor structure, thereby eliminating the drawbacks first mentioned above. Nevertheless, this embodiment suffers from the difficulty of requiring a very long cavity capable of receiving practically the whole length of the cover when this is withdrawn to reveal the mirror, within the internal structure of the sun visor body. The relatively large dimensions of the cavity cause problems for an adequate location of the sun visor components such as: its internal framework; the hinge body; the electrical illumination means where the sun visor is provided with independent light sources. These drawbacks are overcome in part in European patent No. EP 0099454, which describes a cover for a sun visor mirror made from flexible material which is capable of being concealed within the sun visor body when the mirror is uncovered, in three different ways: a) folding back in a large loop requiring an internal housing situated as an extension of the mirror and having a length equal to half the total length of the cover body; b) by being rolled up around a spool located at a side of the mirror; and, c) by sliding linearly, i.e. without being wound up or forming loops, towards a housing which is situated behind the mirror body. It should be noted that in all three cases a), b) and c) described, it is absolutely necessary for the cover to be made from flexible material, such as a thick fabric or a flexible plastic band or tape. This constitution may cause jamming because of uncontrolled friction or the formation of small folds. Also the edges contacting the guides are subject to wear which doubtlessly is more intense with the common flexible materials. To combat this harmful phenomenon, it would be necessary to use expensive specially resistant materials. A further negative factor of the embodiments described in European patent EP 0099454 lies in the relative mechanical complexity of the means designed to house the flexible cover, which also affects the production costs, making them relatively high.